For flash the input/output is the same, but the cache difference is big, you're paying 10x on >95% of your tokens.
For Pro, it's even worse, input/output is 4x and cache is 40x. The price different is really brutal. Yes you will still come out ahead by spending your first 10$/month on opencode go, but you will be saving a lot less than initially appears from their (60 USD for 10 USD pitch).
Per the open code zen pricing page[1], it appears that the token prices are the same, but their cache is 10x more expensive?
[1]: https://opencode.ai/docs/zen/#pricing